RESPONSE OF SEASHORE PASPALUM GENOTYPES TO DOLLAR SPOT DISEASE

摘要

Seashore paspalum (Paspalum vaginatum Swartz) is a warmseason grass with several attributes widely used for golf courses due to its fine to medium leaf texture.Dollar spot caused by Sclerotinia homoeocarpa is one of the most significant diseases of seashore paspalum.The disease is primarily managed using fungicides; however resistance to fungicides has been documented.Plant resistance plus integrated management could be the best alternative to prevent the onset of the disease.Most seashore paspalum cultivars are reported as being susceptible to dollar spot under natural conditions.Efficient screening techniques and knowledge regarding the inheritance of dollar spot response would be beneficial for seashore paspalum breeding programs.Several thousand seedlings from eleven half-sib families were inoculated three times under high disease pressure.From approximately 500 surviving seedlings 47 were selected for two additional inoculations.After inoculations the progeny genotype percent severity ranged from 22 to 41 and family mean percent severity ranged from 22 to 37.High variance indicated that genetic effects are contributing to different disease responses.The narrow sense heritability was 23%.Breeding values indicated that there are some genotypes and families with better and worse disease response than ‘Sea Isle Supreme’.Data suggest that the screening methodology allowed for both forward and reverse selection of progeny and parents with improved disease response to dollar spot.